One of the most well-known scientists to explore the use of heart rate for the purpose of athletic improvement was Francesco Conconi. His research resulted in what is known as the "Conconi Test". As part of this test, athletes monitor heart rate response to increases in speed. Conconi thought when heart rate and speed were are plotted on a graph, lactate threshold occurred when heart rate no longer climbed in a linear relation to speed. He believed this is the point was directly related to the accumulation of lactate in the body.

Actual lactate accumulation in the muscle can only be measured by drawing blood samples. Conconi's work helped athletes and coaches utilize tools such as a heart rate monitors to gauge the body's response to exercise without expensive and inconvenient laboratory tests.

Conconi and his assistants used lactate threshold information to help Francesco Moser break the World Hour Record on the bike. Conconi publishing of his heart rate theory information led several other scientists and coaches to begin basing their training methods on zones and the popular Russian based per iodization theory.

Although many coaches use Conconi's work as the foundation of their training zones, not everyone agrees that Conconi's or the use of heart rate monitoring to improve performance, is valid in itself. Some argue a VO2 Max measurement ( a measurement which determines oxygen consumption efficiency) is need to better determine the deflection point; the relationship between heart rate and lactate threshold; the relationship between heart rate and ventilatory threshold; and the relationship between heart rate, lactate threshold and different sport activities.

Why Use Heart Rate Monitor for Training? There are several reasons that coaches and athletes have used heart rate monitoring and feedback as a training tool. A few of the reasons include: •Inexpensive and non-invasive approach to acquiring body feedback
•Easy way to determine the various stages of energy production
•Easy way to estimate the rate of energy expenditure
•Allows athlete establish training zones
•Monitors can be a gauge to limit pace
•Set and/or gauge training paces
•Helps identify abnormalities in heart rate allowing you to potential identify an upcoming cold)

One issue with heart rate is that it does vary with environmental conditions such as heat and humidity. It also varies with an individual's hydration, nutrition and sleep status. Training sessions from previous days and weeks influence heart rate, including the positive effects. Illness, stress and injury can affect heart rate. Stimulants such as caffeine, or any other drug, whether it is prescription or over-the-counter, can affect heart rate and LT values.

Use your heart rate monitor in conjunction with other training tools such as Perceived Level of Effort, power meters, cadence, speed, altimeter, etc . By understanding the variables and through the use of these other tools, athletes become much more informed about their performance and enable themselves to make desired improvements.